Iruka does, of course, notice the cleverly done bug placements and the badly done genjutsus that follow after. He is a chunin, after all. Maybe not stellar enough to become jonin, but not actually a bad one. He simply doesn’t say anything, because he’s also noticed that it’s being done in defense of his favorite student. Maybe he shouldn’t play favorites, but it’s not like Naruto has parents to love him and pamper him. He can’t be a parent to him, but he does what he can. Besides, he doesn’t like to discourage cleverness and creativeness, and Ino’s bug tosses at least have that.
It doesn’t hurt that she’s only doing it to people who are more interested in being bullies than in learning something useful. Sure, all the kids learn, but ninja need to be exceptional, and the fact that none of them have figured out who is pranking them after weeks of it means that they really are less than suited to be ninja, no matter what their grades say.
A good fifth of them haven’t even figured out that they are being pranked and a few of them begin to whisper about curses. Ninja really need to be more discerning than that. Most of the rest of them think Naruto is the prankster. Like Naruto’s that subtle?
So Iruka just observes instead of intervening.
What he learns is surprising.
It seems that Naruto is no longer entirely alone, a shocking, positive thing. Not only is Ino, and later Shino too, defending Naruto (who is clueless), Sakura is aiding him as well. Exempting him from the genjutsus that he never seems to notice, and teaching him enough about classwork that his grades go up noticeably. That’s impressive. Naruto’s attention is hard to hold on a good day, much less get him to be interested enough to actually learn something. The boy is smart, but hyper, the very definition of yang energy. Too hot blooded to hold still. (Well, not actually hot-blooded. The kid wears that jacket no matter what.)
But it’s not just Naruto who is affected by this change in dynamics.
Hinata Hyuuga pushes herself as she sees Naruto improving and gets past her fear of hurting others to train correctly. Some of the more obnoxious lazy brats have learned the hard way that she is a lot stronger than her personality makes her seem. Kiba and Choji actually learn to recognize genjutsu in action (courtesy of Akamaru’s nose noticing the lack of scent to the insects) and learn counters for it. He’d despaired of them ever learning such subtlety.
Shino is actively interacting with someone of his own accord. Startling in the extreme for an Aburame, and encouraging. Ino’s paying more attention in class. Which is great, because he’d despaired of getting the obviously intelligent girl to do anything but paint her nails and play with her hair despite technically doing well in all her classes. And Sasuke’s aloof and disinterested expression that hides deep, deep anger has changed to a semi-permanent expression of baffled annoyance and ‘Oh Kami, why is this my life?’ Which eases his worry about the kid.
Sakura is more focused, which looks good on her. And Shikamaru actually looks interested around his pretense of constant naps in class. It’s hard to get Naras interested in much of anything, really. They tend to work things through about twenty moves in advance. The fact that it has kept Shikamaru’s interest probably means that there is more to it than Iruka is seeing, but he doesn’t mind that.
Iruka’s not sure where the change originates from. These are different students than were in class with Naruto last year, so it’s hard to tell. But whatever it is, he likes it.
It gives him hope.
Naruto is no longer alone, and for whatever reason, that simple fact has changed not one, but nine of his students, a good quarter of his class, for the better. He has a good idea of which of his students will make it past genin rank, unless something changes drastically. Maybe he’ll slip them a few safe techniques under the guise of extra credit work and see what they do with it.
Now. If Sakura can just get Naruto up to speed enough on classes that Iruka can pass him this year, everything will be great.